Electric heating unit for heating container space to variable temperature with constant electric current

摘要

An apparatus for heating the contents of a container having a base with a planar heat conducting surface of predetermined shape. The apparatus includes a planar heat radiating surface of the same predetermined shape and a planar support surface for supporting the container in a stable position such that the heat conducting surface overlies the heat radiating surface. The support surface has a vertical projection in the plane of the heat radiating surface which is not coextensive with the heat radiating surface at any point. A mechanism is provided for adjusting the position of the support surface relative to the heat radiating surface in a direction perpendicular to the latter. The adjustment mechanism includes at least three rows of recesses, the recesses of each row being arranged in an ascending pattern and the rows being circumferentially distributed at equal angular intervals, and at least three projections circumferentially distributed at the same equal angular intervals. Each projection engages a respective recess of a corresponding row when the container support surface is in a corresponding position.